Just found out today that only the usb 4.0 port above the audio-out on the back panel has x4 pcie 4.0. The usb 4.0 port above the magnetic power-in has x2 pcie 4.0.
It's not an issue for me, I just thought it was good to know (maybe for others as well) using ITGZ asm2464pd external nvme enclosure and Fanxiang s880 drive.